Friday, December 23, 2011

The evidence for evidentialism is no such thing

The evidentialist view is that relations between your non-factive mental states and your beliefs determine what your evidence is and thereby which propositions you justifiably believe. Your beliefs are justified you have sufficient evidence for your beliefs (and you believe for the right reasons). Some evidentialists adhere to a strict ethics of belief, one according to which for any body of evidence there is one and only one attitude (believe, disbelieve, or suspend judgment) you can justifiably take towards the propositions you consider.

What evidence is there for evidentialism? Some evidentialists argue for evidentialism on the grounds that relations between your beliefs and your evidence determine whether your beliefs are rational or reasonable from the epistemic point of view. If justified beliefs are reasonably held beliefs and reasonably held beliefs are justified, it follows that your beliefs are justified if they are supported by sufficient evidence and unjustified otherwise. Others argue for evidentialism on the grounds that alternative views are faced with a version of Moore’s Paradox (Smithies 2011).

Suppose (if only for reductio) that the accessibility thesis (the conjunction of the positive and negative accessibility thesis) is false:

PAT: You have justification to believe p iff you have justification to believe that you have justification to believe p.

NAT: You lack justification to believe p iff you have justification to believe that you lack justification to believe p.

If the accessibility thesis is false, you can have simultaneous justification for certain doxastic attitudes that are not rationally co-tenable. (They are not rationally co-tenable because they give rise to an epistemic version of Moore’s Paradox.) If they are not rationally co-tenable, they cannot be attitudes that you have simultaneous justification for holding. So, the accessibility thesis is not false.

Now, consider the pragmatist view. The pragmatist thinks that you can have sufficient justification to believe p even if you have equally good evidence for p and for ~p—provided that forming the belief that p will further some significant practical end. (In cases where there is sufficient evidence for believing p or believing ~p, the evidentialist and pragmatist views agree that your beliefs are justified only if they conform to the available evidence.) I ask you to consider the view not because it is true (I have nothing but contempt for the view), but because I think it is a contingent matter whether anyone has sufficient evidence to believe it. Raised on a steady diet of pragmatist propaganda, it seems someone just might have sufficient evidence to believe that she has sufficient justification to believe p where she does not also have sufficient evidence that p is true. PAT implies that if our subject permissibly believes that she permissibly believes (say) God exists (where she has no more evidence that God exists than she does for the hypothesis that God does not exist), she permissibly believes that God exists even though she violates the evidentialist’s standards.

Here, now, is my anti-evientialist argument. William has sufficient justification to believe that he permissibly believes that he permissibly believes God exists. William, however, does not have sufficient evidence to believe that God exists. So, according to PAT, it is permissible to believe without sufficient evidence. According to the evidentialist, it is never permissible to believe without sufficient evidence. Thus, the evidentialist view is mistaken.

The evidentialist can respond by rejecting my claim that it is possible for someone to have sufficient evidence to believe the pragmatist view or by rejecting PAT. The first response is completely ad hoc since the evidentialist view is that the evidence you have depends upon psychological facts about you (e.g., what you seem to remember, what you find intuitive, how things look to you, etc.). Surely if by virtue of some contingent psychological facts someone can have sufficient evidence to believe evidentialism, someone can have sufficient evidence to believe pragmatism. Suppose instead that the evidentialist rejects PAT. If they do so, they have to dispense with one of the arguments for evidentialism. Is that all that damaging to the view? Not necessarily. There are other arguments for evidentialism. For example, there is the view that the justified belief just is the rational belief. The thesis S’s belief is rational iff it is justified (R=J) seems to support evidentialism because it seems natural to assume that following the evidence is what the rational person does. It is often what the rational person does, but perhaps the rational person follows the evidence and comes to believe that pragmatism is true. If the subject discovers that she holds beliefs that conform to the pragmatist’s standards, it might seem that her beliefs are rationally retained even if the subject’s beliefs do not conform to the evidentialist’s standards. (Perhaps the subject is non-culpably ignorant of the fact that she does not live up to the evidentialist’s standards.) If so, R=J does not support the evidentialist view. Indeed, R=J would seem to suggest that the evidentialist’s view is mistaken.

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Richard (in the comments) asked what I think is _the_ question to ask. I've offered a sketch of an answer. Adequate? Well, if not yet, hopefully soon. Thanks, RC.

8 comments:

Is evidentialism compatible with holding that, say, any non-factive mental states provide one with sufficient "evidence" for a priori philosophical truths (and against their negations)?

If so, then -- given that epistemic pragmatism is a priori false -- it doesn't seem so "ad hoc" to deny that pragmatism could be justifiably believed. One might have a quite general account of a priori justification which yields this result.

The evidentialist view (that I have in mind) allows for justified, false beliefs about contingent matters, but it also says that justification supervenes upon facts about a subject's non-factive mental states. Since the necessary truths supervene upon these truths, you're right that the evidentialist _could_ say that there are no justified, false beliefs about, say, whether evidentialism is true, whether reliabilism is true, whether utilitarianism is true, etc.

The question, however, is whether they'd want to say that epistemic pragmatism is apriori false and dispense with the objection that quickly. I'm not quite sure what "apriori false" means. If it's just some falsehood that can be known to be false apriori, there's nothing obviously wrong with saying that some subject justifiably believes p where p is apriori false (think about Frege's axiom V). If it means something that's false that everyone has adequate justification to believe to be false, then I suppose you couldn't say that someone justifiably believes p where p is an apriori falsehood, but that's just because the assertion that p is apriori false is basically the bald assertion that nobody could justifiably believe it. There's no explanation here.

I was assuming that the evidentialist would want to say that the beliefs we have about evidentialism, pragmatism, etc. are justified only if supported by evidence and that the evidence has to be understood in such a way that we can have adequate evidence (provided by intuition, say) even if it concerns a proposition that 'turns out' to be false. I don't think the evidentialist would want to say that nobody could have _any_ evidence for rival views. They don't want to say that anybody who has evidence against evidentialism also happens to have evidence for evidentialism. (Having evidence always involves being in some psychological states you don't have to be in.) So, what right do they have to say that while somebody could have evidence against evidentialism and no evidence for evidenitalism, the evidence for rejecting evidentialism is never enough to make believing evidentialism false rational? None, so far as I can see.

I guess I was thinking that we might always have sufficient evidence for believing a priori truths, insofar as they don't require any particular (empirical) evidence at all. So even if one has some misleading empirical evidence (from testimony, etc.) for believing pragmatism, it seems natural to think that this must be outweighed by whatever happen to be the reasons for thinking evidentialism is true -- reasons that are (I'm supposing) "accessible" in the relevant sense no matter what your contingent psychological states.

I'm not sure whether they'd rather go this route or deny PAT. Insofar as one thinks there can be justified false beliefs in general, it seems odd to deny (as PAT effectively does) that there could be justified false (higher-order) beliefs about the justificatory status of one's own beliefs.

PAT seems most plausible if we're talking about ideal rationality. Otherwise, I don't see why people couldn't be simultaneously "justified" in some weaker sense -- "not blatantly unreasonable", say -- in holding two compartmentalized beliefs that happen to be in rational conflict (or not "co-tenable", as you put it).

But if we're talking about justification-as-ideal-rationality, then it's trivial that all a priori truths, and no a priori falsehoods, are justified. (And also that justification, in this sense, supervenes on one's non-factive mental states.)

I don't think we can have sufficient evidence for believing apriori truths if, say, those include complicated mathematical or moral facts. Just to fill in some detail, Conee and Feldman identify two ways in which we can acquire apriori justification: - knowledge of conceptual relations; - intuitions about cases that we can then use to confirm (inductively) or disconfirm a view. (In their contribution to Q. Smith's OUP collection in 2008.)

If p can be intuitive even if ~p (something they seem to think) then I don't think they can say that it's impossible for someone to have evidence that favors a false philosophical claim and no evidence against it.

You might be right that PAT might be defensible if we're interested in ideal rationality, but I worry that focusing just on ideal rationality, PAT won't provide us much reason at all to reject views like reliabilism that are not about ideal rationality but just ordinary justification.

Epistemology of religion? This will come down to one person saying "I have an intuition that there is a god" and another holding " I have an intuition that there is no god" or "I have no intuition either way". These are bedrock premises in effect and impervious to argument. One could argue further that allpositions boil down to such intuitions as premises, including what constitutes evidence or does not. Something is the case to one that is not the case to another--happens all the time. To each of us arises something that is the case, even if it is that we don't know what is the case. And it may be so compelling as to be a permanent fixture of the person. Are these facts? Something will arise to you that says yes or no or otherwise. That something arises and arises as the case---is, it seems to me, the best expression of what is fundamental. To those with a bedrock intuition, justification is a matter after the fact. One of course is not bound to hold the same premises as another.

First, you think NAT is true? Don't all kinds of things (ie. non-doxastic agents, those w/o the concept of justification) lack justification for believing things w/o justification for believing this of themselves?

Second, doesn't the Moorean problem you allude to with PAT and NAT only arise if someone is justified in believing the conjunction (and not simply from the conjunction being true)? It seems that way to me. The evidentialist can claim that though the conjunction can be true, you can't be justified in believing it (one of the conjuncts would be defeated).

About the argument though, is the justification that the Pragmatist is talking about epistemic justification (ie. the same thing the evidentialist is talking about)? If not, then disambiguated there is no problem. If so, then I don't see why the subject doesn't have sufficient evidence to believe God exists. She has sufficient reason to believe [pragmatism and if progmatism then believe God exists]. If the evidence supported reliabilism and that a particular belief was the result of a reliable process, I think the evidence would support that particular belief. Misleading evidence in either case, but evidence nonetheless.

The evidentialist view under consideration is not a view concerning religious epistemology. It's a view that is supposed to apply to all beliefs. And I don't buy the idea that it boils down to intuitions. People are committed to claims about God that I think are quite clearly false (e.g., claims about the way the world would be if there were an all-powerful and all-knowing being monitoring it at all time who had unlimited power).

Hi Jon,

I think this is supposed to be limited to rational agents. I think I agree with you about the conjunctions. My own view is that you cannot justifiably believe both conjuncts but might have reasons to believe the conjuncts. The access theses here are theses that Smithies defends in a PPR paper where he ultimately wants to defend a version of mentalism. I think that his access theses cause trouble for the evidentialist idea that you cannot justifiably believe without evidence.

As for the disambiguation, I guess I don't see why that would help defuse the problem. Someone can have evidence for the false philosophical view that you can have the epistemic right/justification to believe without evidence. That's the key point. Evidence that I don't need evidence to have the right to believe p is not evidence for p (or p's negation), so if the evidence is _sufficient_ to justifiably believe that I am justified in believing p without evidence, one of the access theses asserts that I do have epistemic justification to believe without evidence. Myself, I think you cannot justifiably believe what you know you don't have evidence for, but for the purposes of my post all that matters is that it is very difficult to argue from the access theses to evidentialism.

A belief isn't subject to justification. As a belief is the personal decision to act on one of two or more unproved or unprovable public propositions, justifications are always going to be in the publc domain, not the private.